In the fictional Middle-earth created by J. R. R. Tolkien, Ephel Dúath is the name for the Mountains of Shadow that guard Mordor's western and southern borders. Their Sindarin name means literally "outer fences of dark shadow". They meet the Ered Lithui at the Morannon (Black Gate), so that between them the mountain ranges effectively seal off Mordor from invasion on three sides. The Pass of Cirith Ungol leads through the Ephel Dúath from the Stairs of Cirith Ungol behind Minas Morgul to the Tower of Cirith Ungol.
